pyrophosphatase

[pī′rə-fŏsfə-tās′, -tāz′]
n.
  1. Any of various enzymes that selectively cleave a pyrophosphate situated between two phosphoric groups, leaving one phosphoric group on each of the two fragments.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.